High-Frequency Ablation Medical Device for Pancreatic Cystic Lesion, Having Self-Expanding Spherical Electrode Embedded Therein

This study is related to the Development of a Self-Expandable Electrode Catheter System for Local Thermal Therapy for Malignant Biliary Strictures (Project Unique Number: 1711196795, Project Number: RS-2023-00238092) of the Pan-Ministry Full-cycle Medical Device Research and Development Project, conducted at Asan Medical Center in Seoul, supported by the Pan-Ministry Full-cycle Medical Device Research and Development Project Group funded by the Korea government (Ministry of Science and ICT, Ministry of Trade, Industry and Energy; Ministry of Health and Welfare; and Ministry of Food and Drug Safety), and the Research on Stent-Based Irreversible Electroporation Hybrid Technique for the Treatment of Gastrointestinal Strictures (Project Unique Number: 1711186905, Project Number: 2022R1C1C1003205) of the New Researcher Support Program, conducted at Asan Medical Center in Seoul, supported by the National Research Foundation of Korea funded by the Korea government (Ministry of Science and ICT).

In general, the treatment of cystic lesions of the pancreas is performed by surgical resection when the lesion is judged to cause symptoms or has a risk of malignancy; otherwise, patients are monitored periodically through follow-up observations. Despite advances in surgical techniques, the postoperative morbidity rate remains relatively high, reported to be as much as 15% to 30%, and it is difficult to accurately determine the risk of malignancy with only imaging findings and tissue specimens obtained by endoscopic ultrasonography, so this treatment method may be insufficient for managing various pancreatic cystic lesions. In addition, as the understanding of pancreatic cystic lesions deepens, the criteria for surgical indications have become increasingly stringent. Therefore, there is a need to develop treatment methods that are relatively safe, minimally invasive, and yet effective.

In line with these changes, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has recently been employed for minimally invasive endoscopic ultrasound-based treatment. Radiofrequency ablation is a technique that treats lesions using a heat-generating probe, and EUS-RFA is performed by directly accessing pancreatic and peripancreatic lesions through the walls of the stomach and duodenum.

In this method, a fine needle-shaped electrode is used to access the pancreas, and a thin micro-needle electrode is required for treatment of regions such as the uncinate process or the head of the pancreas. While the fine needle-shaped electrode is advantageous for access, it requires repeated procedures in a fan-shaped manner with different directions after reaching the lesion, and in the case of the micro-needle, its slender structure may limit the feasibility of repeated ablations.

(Patent Document 1) Korean Patent Application Publication No. 10-2021-0079083 (Published on Jun. 29, 2021)

Embodiments of the present disclosure have been devised in view of the aforementioned background, and are intended to provide a radiofrequency ablation medical device for pancreatic cystic lesions, equipped with a self-expandable round electrode that facilitates access to the lesion site and the ablation procedure.

A radiofrequency ablation medical device according to one embodiment of the present disclosure includes: a guide catheter movable to a lesion site of an organ; and an electrode catheter disposed in the guide catheter to be inserted through and to protrude out from an end of the guide catheter, and including a shape memory electrode for ablation of the lesion site, wherein the guide catheter includes: an outer tube; an inner tube having an outer surface spaced apart from an inner surface of the outer tube, and a catheter passage through which the electrode catheter is movable; and a suction channel formed between the outer tube and the inner tube to aspirate lesion fluid generated at the lesion site

Further, the guide catheter may further include a support member arranged in the suction channel to support the outer surface of the inner tube and the inner surface of the outer tube.

Further, the guide catheter may further include a handle having an end to which the outer tube and the inner tube are connected and a passage through which the electrode catheter passes.

Further, the handle may include: a handle body part including a handle passage through which the electrode catheter is movable; a handle suction part formed to be in communication with the suction channel to provide suction force to the suction channel; and a handle fixer part for securing the electrode catheter.

Further, the end of the guide catheter may have a fine needle shape that is formed to be inclined in a longitudinal direction.

Further, the electrode catheter may include: a moving rod configured to move along the catheter passage; the shape memory electrode, disposed at one end of the moving rod and configured to retain a shape corresponding to an expanded state thereof, and a catheter pusher connected to the other end of the moving rod.

Further, when expanded, the shape memory electrode may provide a mesh structure having a shape corresponding to a shape of the lesion site to be in close contact with the lesion site.

Further, the shape memory electrode may protrude out from the guide catheter when the catheter pusher is moved relative to the guide catheter in a direction approaching the guide catheter, and be retracted into the guide catheter when the catheter pusher is moved relative to the guide catheter in a direction away from the guide catheter.

According to embodiments of the present disclosure, by providing the spherical, self-expandable shape-memory electrode inside the fine needle-shaped catheter, it is possible to improve accessibility to the lesion site and the ablation procedure.

Further, according to embodiments of the present disclosure, the end of the guide catheter is formed in a fine needle shape and the electrode catheter having a shape memory electrode is disposed inside the guide catheter, which enables radiofrequency ablation at the lesion site to be performed with ease.

Furthermore, according to embodiments of the present disclosure, lesion fluid (e.g., cyst fluid) within the lesion site can be aspirated through the fine needle-shaped end of the guide catheter, which reduces the risk of complications such as seeding, and enables precise targeting of the lesion.

In addition, according to embodiments of the present disclosure, by placing the shape memory electrode at the fine needle-shaped end of the guide catheter, the shape memory electrode can self-expand into a round shape after the lesion fluid is aspirated from the lesion site, which enables treatment of the lesion without repeated procedures.

Hereinafter, a preferred embodiment of the present disclosure for implementing the spirit of the present disclosure will be described in more detail with reference to the accompanying drawings.

However, in describing the present disclosure, detailed descriptions of known configurations or functions may be omitted to clarify the present disclosure.

When an element is referred to as being ‘connected’ to, ‘supported’ by, ‘accessed’ to, ‘supplied’ to, ‘transferred’ to, or ‘contacted’ with another element, it should be understood that the element may be directly connected to, supported by, accessed to, supplied to, transferred to, or contacted with another element, but that other elements may exist in the middle.

The terms used in the present disclosure are only used for describing specific embodiments, and are not intended to limit the present disclosure. Singular expressions include plural expressions unless the context clearly indicates otherwise.

Further, in the present disclosure, it is to be noted that expressions, such as the upper side, the lower side, and the side surface, are described based on the illustration of drawings, but may be modified if directions of corresponding objects are changed. For the same reasons, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings, and the size of each component does not fully reflect the actual size.

Terms including ordinal numbers, such as first and second, may be used for describing various elements, but the corresponding elements are not limited by these terms. These terms are only used for the purpose of distinguishing one element from another element.

In the present specification, it is to be understood that the terms such as “including” are intended to indicate the existence of the certain features, areas, integers, steps, actions, elements, combinations, and/or groups thereof disclosed in the specification, and are not intended to preclude the possibility that one or more other certain features, areas, integers, steps, actions, elements, combinations, and/or groups thereof may exist or may be added.

Hereinafter, a specific configuration of a radiofrequency ablation medical device according to one embodiment of the present disclosure will be described.

1 4 FIGS.to 10 10 100 200 Referring to, a radiofrequency ablation medical deviceaccording to one embodiment of the present disclosure can facilitate radiofrequency ablation at a lesion site by using a fine needle-shaped end. The radiofrequency ablation medical devicemay include a guide catheterand an electrode catheter.

100 100 100 Specifically, the guide cathetermay be provided in the form of a probe that can be moved toward a lesion site of an organ. The guide cathetercan access the lesion site under the guidance of endoscopic ultrasound. As an example, the guide cathetercan access a cystic lesion site of the pancreas under the guidance of endoscopic ultrasound.

100 100 100 100 110 120 130 140 150 The end of the guide cathetermay be formed in a fine needle shape that is inclined in a longitudinal direction. In the present embodiment, the end of the guide catheteris formed in a fine needle shape, but without being limited thereto, the end of the guide cathetermay be shaped in various pointed forms that allow easy access to the lesion site. The guide cathetermay include a handle, an outer tube, an inner tube, a suction channel, and a support member.

110 120 130 110 200 110 110 111 112 113 The handlemay be provided in the form of a grip that can be held by a user. An outer tubeand an inner tubemay be connected to an end of the handle. A passage through which the electrode cathetercan pass may be formed inside the handle. The handlemay include a handle body part, a handle suction part, and a handle fixer part.

111 111 200 111 111 111 112 111 113 111 The handle body partmay provide a handle passageP through which the electrode cathetercan move. The handle passageP may be formed to penetrate the handle body part. The handle body partmay be formed in a grip shape that is easy for a user to hold. The handle suction partmay be formed to be inclined at an upper portion of the handle body part, and the handle fixer partmay be disposed at a rear end of the handle body part.

112 140 112 112 140 112 140 112 The handle suction partmay be formed to be in communication with the suction channel. When negative pressure is applied to the handle suction part, the handle suction partmay provide suction force for aspirating lesion fluid from the lesion site to the suction channel. When suction force is applied through the handle suction part, the lesion fluid may be discharged to the outside through the suction channeland the handle suction part.

113 200 113 111 113 113 200 113 111 113 200 113 111 113 200 The handle fixer partcan provide a locking function for securing the electrode catheter. The handle fixer partmay be rotatably disposed at the rear end of the handle body part. When the handle fixer partis rotated, the handle fixer partcan selectively secure the electrode catheter. For example, when the handle fixer partis rotated in one direction relative to the rear end of the handle body part, the handle fixer partcan be brought into close contact with to the electrode catheterto lock it in place, and when the handle fixer partis rotated in the other direction relative to the rear end of the handle body part, the handle fixer partcan release the fixation of the electrode catheter.

120 130 130 120 120 110 120 130 120 130 130 210 120 130 130 210 140 110 The outer tubemay be provided in the form of a tube that can entirely surround the inner tube. The inner tubemay be inserted and withdrawn through a front end of the outer tube, and a rear end of the outer tubemay be connected to the handle. The outer tubemay have an inner diameter larger than an outer diameter of the inner tube. A distance between an inner surface of the outer tubeand an outer surface of the inner tubemay be smaller than a distance between an inner surface of the inner tubeand an outer surface of a moving rod. When the distance between the inner surface of the outer tubeand the outer surface of the inner tubeis smaller than the distance between the inner surface of the inner tubeand the outer surface of the moving rod, the suction channelcan effectively aspirate lesion fluid from the lesion site even with a small suction force applied through the handle.

130 200 130 130 200 130 200 130 120 140 130 120 130 120 The inner tubemay be provided in the form of a tube that can entirely surround the electrode catheter. The inner tubemay provide a catheter passageP through which the electrode catheteris movable. The inner tubemay have an inner diameter larger than an outer diameter of the electrode catheter. The inner tubemay be disposed inside the outer tubewith a spacing therebetween to define the suction channel. The inner tubemay have the outer diameter smaller than the inner diameter of the outer tube. In addition, a thickness of the inner tubemay be the same as or thicker than a thickness of the outer tube.

140 120 130 140 140 140 140 The suction channelmay be formed between the outer tubeand the inner tube. In the suction channel, the lesion fluid generated at the lesion site can be moved. One end of the suction channelcan aspirate the lesion fluid generated at the lesion site when suction force is applied to the other end of the suction channeland negative pressure is generated within the suction channel.

140 100 140 100 140 100 140 100 In the present embodiment, the longitudinal cross-sectional area of the suction channelis formed in the same shape along the extension direction of the guide catheter, but without being limited thereto, the longitudinal cross-sectional area of the suction channelmay be formed in different shapes along the extension direction of the guide catheter. For example, the longitudinal cross-section of the suction channellocated at a front end (one end) of the guide cathetermay be larger than the longitudinal cross-section of the suction channellocated at a rear end (the other end) of the guide catheter.

150 130 120 140 150 130 120 140 150 130 120 150 150 130 120 150 100 130 120 150 130 120 150 100 150 150 120 120 130 150 120 130 150 140 The support membermay be arranged between the inner tubeand the outer tubeso that the suction channelis formed. The support membermay support the outer surface of the inner tubeand the inner surface of the outer tubewithin the suction channel. A width of the support membermay correspond to the spacing distance between the inner tubeand the outer tube. The support membersmay be provided as a plurality of support membersdisposed to be spaced apart from each other in the circumferential direction between the inner tubeand the outer tube. The plurality of support membersmay also be spaced apart from each other in the extension direction of the guide catheterbetween the inner tubeand the outer tube. For example, three support membermay be disposed to be spaced apart from each other between the inner tubeand the outer tube. The three support membersmay also be spaced apart in the extension direction of the guide catheter. The width of the support member, that is, the length of the support memberextending in the circumferential direction of the outer tube, may be shorter than the distance between the inner surface of the outer tubeand the outer surface of the inner tube. When the width of the support memberis shorter than the distance between the inner surface of the outer tubeand the outer surface of the inner tube, the resistance of the support memberto the movement of the lesion fluid through the suction channelcan be minimized.

200 200 220 200 100 200 110 200 100 200 110 200 100 200 210 220 230 When the electrode catheteris positioned at a lesion site of an organ, the electrode cathetercan perform thermal ablation on the lesion site through a shape memory electrode. The electrode cathetermay be movably disposed inside the guide catheter. When the rear end of the electrode catheteris pushed from the handle, the leading end of the electrode cathetercan protrude from the end of the guide catheter, and when the rear end of the electrode catheteris pulled from the handle, the leading end of the electrode cathetercan be retracted into the end of the guide catheter. The electrode cathetermay include a moving rod, a shape memory electrode, and a catheter pusher.

210 130 100 220 210 230 210 230 110 210 130 100 The moving rodmay be made of a flexible material that can be moved along the catheter passageP of the guide catheter. The shape memory electrodemay be disposed at a leading end of the moving rod, and the catheter pushermay be connected to a rear end of the moving rod. When the catheter pusheris pushed or pulled from the handle, the moving rodmay be moved forward or backward along the catheter passageP of the guide catheter.

220 210 210 220 The shape memory electrodemay be fixed to an outer surface of the moving rodat the front end of the moving rod. When power is supplied from a separate energy supply device, the shape memory electrodecan perform thermal ablation on a lesion of an organ using thermal energy (radiofrequency energy).

220 220 220 220 220 100 210 The shape memory electrodemay be made of a shape memory material capable of restoring the shape of its expanded shape. When expanded, the shape memory electrodemay provide a mesh structure having a shape corresponding to the shape of the lesion site, allowing close contact with the lesion site. For example, the shape memory electrodemay be a unitary nitinol wire with shape-memory properties. As a matter of course, the shape memory electrodemay be composed of various types of shape memory materials capable of restoring the shape of the expanded state in addition to the nitinol wire. Further, when contracted, the shape memory electrodecan be retracted into the guide catheterwhile wrapping around the outer surface of the moving rod.

220 220 220 220 When expanded, the shape memory electrodemay have a shape corresponding to the lesion site of an organ, allowing it to closely confirm to and contact the lesion site. For example, the shape memory electrodemay have a spring shape that is twisted into a spiral shape to have an outer diameter corresponding to the inner diameter of the lesion site. In a state where the shape memory electrodeis in contact with the lesion site, the shape memory electrodecan perform radiofrequency thermal treatment on the lesion site by applying thermal energy to the lesion site.

230 220 230 210 230 100 100 220 100 230 100 100 220 100 The catheter pushermay be provided in the form of a handle for moving the shape memory electrode. The catheter pushermay be connected to the other end of the moving rod. When the catheter pusheris moved relative to the guide catheterin a direction approaching the guide catheter, the shape memory electrodemay be deployed from the guide catheter. When the catheter pusheris moved relative to the guide catheterin a direction away from the guide catheter, the shape memory electrodemay be retracted into the guide catheterfor retrieval.

Hereinafter, the operation and effects of a radiofrequency ablation medical device having the configuration described above will be described.

5 FIG. 10 10 21 20 10 21 22 Referring to, in order to guide the radiofrequency ablation medical deviceto a lesion site B of an organ C having a malignant stricture, first, the radiofrequency ablation medical devicemay be moved to the lesion site B through an endoscopic channel partof an endoscopic device. In the present embodiment, the radiofrequency ablation medical devicecan be moved to the lesion site B through the endoscopic channel partunder the guidance of an endoscopic ultrasound part.

6 FIG. 22 20 100 100 10 100 140 Referring to, when the endoscopic ultrasound partof the endoscopic deviceis moved to the lesion site B, the end of the guide catheter, having a fine needle shape, can be advanced to the lesion site B. When the end of the guide catheteris positioned at the lesion site B of the pancreas C, the radiofrequency ablation medical devicecan aspirate the lesion fluid generated at the lesion site through the guide catheterby applying negative pressure to the suction channel.

7 FIG. 100 200 100 220 200 220 Referring to, when the lesion fluid generated at the lesion site is aspirated through the guide catheter, the electrode catheterprotrudes from the end of the guide catheter, so that the shape memory electrodeof the electrode cathetercan expand at the lesion site B. The shape memory electrodecan be deployed and maintained at the lesion site B in a shape corresponding to the shape of the lesion site, which is memorized.

8 FIG. 220 220 220 220 100 10 10 220 Referring to, in a state where the shape memory electrodeis expanded and in close contact with the lesion site B, when power is supplied to the shape memory electrode, the shape memory electrodesupplied with power applies thermal energy to the lesion site B, thereby performing radiofrequency thermal treatment (radiofrequency ablation) on the lesion site B. Thereafter, when the radiofrequency thermal treatment on the lesion site B is completed, the shape memory electrodecan be retracted into the end of the catheterof the radiofrequency ablation medical device, and the radiofrequency ablation medical devicewith the retracted shape memory electrodecan be removed from the lesion site B and moved to its initial position.

As described above, according to the present disclosure, the shape memory electrode capable of self-expanding in a spherical shape is provided inside the fine needle-shaped catheter, thereby improving accessibility and ease of treatment for a lesion site. The end of the guide catheter is formed in a fine needle shape, and the electrode catheter with the shape memory electrode is disposed inside the guide catheter, so that radiofrequency ablation of the electrode catheter for the lesion site can be easily performed. Lesion fluid within the lesion site can be aspirated, which reduces the risk of complications such as seeding, and enables precise targeting of the lesion, and repeated ablation is not required, resulting in reduced procedure time.

The examples of the present disclosure have been described above as specific embodiments, but these are only examples, and the present disclosure is not limited thereto, and should be construed as having the widest scope according to the technical spirit disclosed in the present specification. A person skilled in the art may combine/substitute the disclosed embodiments to implement a pattern of a shape that is not disclosed, but it also does not depart from the scope of the present disclosure. In addition, those skilled in the art can easily change or modify the disclosed embodiments based on the present specification, and it is clear that such changes or modifications also belong to the scope of the present disclosure.